PIP: The monthly distribution of 41,057 births during the period between 1675 and 1816 in Gorlitz, East Germany was investigated by studying old baptism registration books in a church in Gorlitz. In the first 6 year period (1675-1680), the average birth number was about 0.6/day, which was the least among all the periods examined. In the period between 1681 and 1800, the average daily birth number was in the range of 0.66-0.90. This began to increase rapidly after 1781, after the 2nd lowest birth rate (0.66/day) was registered in the period between 1771 and 1780. Between 1675 and 1690, the earliest 16 year period of the series, there were 2 peaks with their respective maxima in March and September. Although the seasonality did not depart much statistically from a uniform pattern, the September peak was the larger of the two in magnitude. After 1691, the spring peak apparently exceeded the fall peak in every decade until 1760. During this 70 year period, the major maximum in each decade was in January, February, or March. The minor fall maximum in each decade was scattered within the months between August and November. Generally, the months for both peaks and the summer trough were a month earlier in the 40 year period between 1721 and 1760 than in the 30 year period between 1690 and 1720. In both periods, the seasonality departed significantly from a uniform pattern. From 1761 to 1780, the spring peak diminished, while the early fall peak in August became predominant. The seasonal deviation was again significant for the period. Between 1781 and 1800, the fall peak collapsed and the maximum in the early spring was the major. The grade of variation among monthly birth ratios was the least during this period, and the seasonal deviation was not significant. The seasonal variation increased again in the 1st decade of the 19th century, and the fall peak was evident again in August-October. During 1811-1816, this pattern was more irregular with a retarded fall peak and higher spring peak in March-April. The presence of these changes in the seasonal distribution of births also has been observed in the U.S., Japan, and other European nations at about the same period.